How many portions should be collected for sampling concrete from revolving drum truck mixers?

Collecting two or more portions at regularly spaced intervals is essential for ensuring representative sampling of concrete from revolving drum truck mixers. This approach addresses potential variability in the concrete mixture that can occur during transportation, as the materials may not be uniformly distributed throughout the batch.

By taking samples at different intervals, the inspector can capture the variations in the concrete's consistency, composition, and grading that could affect its overall quality and performance. This method also helps identify any issues that might arise during mixing or transport, such as segregation or inconsistent admixture distribution.

Overall, sampling at multiple points provides a comprehensive view of the entire batch's characteristics, allowing for more accurate assessments of compliance with specified requirements and enhancing the integrity of the testing results.